"Dumbledore had them hide, had them choose someone to make their Secret Keeper about where they were. At the time, that's all I knew about it." He left out the part where being a werewolf had made him a...less than ideal candidate, because while he understood it, it still stung."
"Dumbledore thought they'd picked you. I thought they'd picked you--you were Harry's godfather, it made sense if it was you. But they didn't use you because you thought you;d be too obvious."
He smiled faintly, sadly, as his voiced cracked slightly. "So they used Peter. Because no one would ever suspect Peter."